LAS VEGAS – The fight the boxing world has been waiting for is finally at hand.

Canelo Alvarez turned in yet another masterful performance, outclassing his countryman Julio Cesar Chavez Jr. to set up a September bout with IBF-WBA-WBC middleweight champion Gennady Golovkin before a T-Mobile Arena-record crowd of 20,510.

“Triple-G, you are next my friend,” Alvarez said. “The fight is done. I’ve never feared anyone since I was 16, fighting as a professional. When I was born, fear was gone.”

The deal was announced while Alvarez was being interviewed in the ring on Saturday. They will fight on Sept. 16.

Alvarez won a unanimous decision from Chavez, battering him around the ring with hard, clean shots from start to finish. All three judges, as did Yahoo Sports, scored it 120-108 for Alvarez, giving him every round.

Every now and then, as if to entertain himself, Alvarez would lay back on the ropes and let his rival throw punches. When he decided he’d had enough of that, he blasted Chavez with something, often a jab, and regained control.

He mixed his punches, going to the body and the head and using both his left and his right. It was a masterful performance, but whether it was because he was that good or because Chavez offered little is in the eye of the beholder.

“Tonight I showed I could move and box,” Alvarez. “I showed as a fighter I could do all things.”

The truth is, it was probably a little of both. For all his pre-fight talk, Chavez did little to cause Alvarez any concern. He never established his jab, fought off a slight crouch that negated his height advantage and did little more than be a punching bag.

Alvarez, though, had the determined look of a killer. He battered Chavez’s ribs, stealing the playbook from Chavez’s father, Julio Sr., who was animatedly watching the fight at ringside.

Chavez Sr. was a terror to the body, and Alvarez, who as a child idolized him, followed suit on Saturday.

“Canelo beat me,” Chavez said. “He beat me at a distance.”

Alvarez was better than a 7-1 favorite at one-point, but the money on fight day was all on Chavez, pushing the closing odds to 4-1. Chavez had the size, a good jab and a hard right, and that made some think at least he could give Alvarez problems.

That never materialized, as he never got started and absorbed a horrific beating for 36 minutes.

The only fight for Alvarez after Chavez had to be the one against the unbeaten Golovkin, which Alvarez promoter Oscar De La Hoya had been promising for more than a year. Last May, after Alvarez knocked Amir Khan out, Alvarez invited Golovkin into the same ring, but the fight wasn’t made.

Golovkin did his part in March to make the bout by defeating Daniel Jacobs, setting up a mega-match which almost certainly would be the year’s richest event.

“I feel very excited,” Golovkin said. “Right now is a different story. In September, it will be a different style — a big drama show. I’m ready. First, congrats to Canelo and his team. Right now, I think everyone is excited for September. Canelo looked very good tonight, and 100 percent he is the biggest challenge of my career. Good luck to Canelo in September.”

While Golovkin will likely be favored, if and when the fight is officially made, Alvarez will give him the hardest test of his career.

It was not much of a test Saturday for Alvarez, who according to CompuBox outlanded Chavez 228-71. Chavez only landed 15 jabs in a stunningly poor performance.

The Golovkin-Alvarez fight will be the talk of the boxing world and will match fighters who have a combined record of 85-1-1 with 67 knockouts.

It figures to be a tense, action-packed affair between two of the most offensive-minded fighters in the sport, as well as two of the hardest hitters.